Reducing every value of a matrice every time by the same value

Hello, I am new at matlab and I have a question. Is it possible to reduce every single value of a nx2 matrix by the same amount until all values are zero? Maybe in a for loop?

[Scott MacKenzie]

Your problem is poorly stated and not solvable without further explanation. For example, if an element in the matrix is, say, 2, and the "same amount" you refer to is, say, 3, then that element will be -1 when it is "reduced". It will never be "zero".

[dpb]

Of course. Math operations by constants on arrays work on the entire array by default.

Of course, hitting zero exactly would require a specific value that is evenly divisible into the original value without rounding so it may or may not work out exactly depending upon the values in the array.

Or, of course, if the values in the array aren't the same, you'd have to compute that difference by dividing by the number of iterations and then do array addition/subtraction which is also array-wide.

Again, floating point rounding can make hitting exactly zero tricky...

[John D'Errico]

Please don't keep on asking the same question. If you want more about this question, then make a comment to Matt's answer, asking him for clarification.

Answer 1

[Matt J]

This might be what you want, but as @Scott MacKenzie says you've left a lot of problem details and issues for us to guess,

while any(matrix(:)>0)

    matrix=max(matrix-something,0);
    
end

[gamer]

Thank you for your fast answers:) I am sorry missing some details.

I programmed n spheres. All of them are getting random speed values in x and y direction.

v = rand(n,2);

This is the speed matrix. Now I want to simulate friction while reducing it with a=0.001 until every sphere isn't moving. If a sphere isn' moving anymore, the value should be zero.

[dpb]

v=rand(n,2);
dv=0.001;
while any(v,'all')
  ...
  v=max(0,v-dv);
end

[dpb]

Oh. I see I just duplicated Matt's answer that was already there...I had just read the comments before.

[gamer]

So first thank you very much for your answers Matt and dpb. Its really that you want to help me!

I tried that one but I think I have to explain the problem more in detail. I created n spheres with that starting location.

p=[r + (a-2*r)*rand(n,1),r + (b-2*r)*rand(n,1)];

Then I wanted to move this spheres. So I created a matrix for speed.

v=rand(n,2);

Then I want to update the position with a for loop.

for f = 1:1000
p = p + v;
end

The movement is working. But I dont get how to slow the balls down. Is it possible to create f = 1000 of matrix out of the first one and the values are always reduced be a=0.001. And if one value is smaller than 0.001, this value should be 0 for the following matrixs

So the for loop would be: p = p + v(f)?